Vehicle drive device

ABSTRACT

A vehicle drive includes a speed change mechanism connected to a rotary electric machine; an output member connected to the speed change mechanism and wheels; an engagement device changes a state of engagement between an input member connected to an engine and the speed change mechanism; a hydraulic pump driven by the engine or the rotary electric machine; a first pressure control device that controls pressure supplied from the pump and supplies the pressure to the speed change mechanism; a second, separate hydraulic pressure control device that controls the pressure supplied from the pump and supplies the pressure to the engagement device; and a case that houses the rotary electric machine, speed change mechanism, engagement device, and pump. At least the engagement device is housed in a space formed by the case, and the second hydraulic pressure control device is provided at a part of the case forming the space.

INCORPORATION BY REFERENCE

This is a Continuation of application Ser. No. 14/317,991 filed Jun. 27,2014, which is Continuation of application Ser. No. 13/659,361 filedOct. 24, 2012, which claims the benefit of U.S. Provisional ApplicationNo. 61/592,225 filed Jan. 30, 2012, which in turn claims the benefit ofJapanese Patent Application No. 2011-242916 filed on Nov. 4, 2011. Thedisclosure of the prior applications is hereby incorporated by referenceherein in its entirety.

BACKGROUND OF THE INVENTION

The present invention relates to a vehicle drive device provided with aninput member drivingly connected to an internal combustion engine, arotary electric machine, a speed change mechanism drivingly connected tothe rotary electric machine, an output member drivingly connected to thespeed change mechanism and wheels, and an engagement device that iscapable of changing the state of engagement between the input member andthe speed change mechanism.

DESCRIPTION OF THE RELATED ART

As conventional techniques of a vehicle drive device such as describedabove, there are techniques described in, for example, Japanese PatentApplication Publication No. 2011-105192 (JP 2011-105192 A) and JapanesePatent Application Publication No. 2010-196867 (JP 2010-196867 A). Notethat, in the description of this Description of the Related Art section,names of relevant members in JP 2011-105192 A and JP 2010-196867 A willbe cited in square brackets. In a structure described in JP 2011-105192A, hydraulic pressure supplied from an electric pump [electric pump 7]is controlled and fed to an engagement device [clutch device 3] arrangedbetween an input member [input shaft 32] and an rotary electric machine[electric motor 1] in a power transmission path, and thus, the state ofengagement of the engagement device is changed. Here, the electric pumpis a hydraulic pump driven by an rotary electric machine dedicated tohydraulic control separately from the rotary electric machine [electricmotor 1] serving as a source of vehicle driving force.

With such a structure, the discharge performance of the pump could beinsufficient if a small-sized pump is used as the electric pump in orderto improve mountability of the vehicle drive device to the vehicle.Although it is conceivable to cover the insufficiency in the dischargeperformance by increasing the number or diameter of friction plates,increasing the number or diameter of the friction plates could lead toan increase in size of the engagement device. Therefore, downsizing ofthe vehicle drive device has its own limits.

JP 2010-196867 A describes a structure in which a hydraulic unit [firstclutch hydraulic unit 6] that controls hydraulic pressure supplied to anengagement device [first clutch CL1] is provided in a hydraulic pressurecontrol device [AT hydraulic pressure control valve unit CVU] thatcontrols hydraulic pressure supplied from a mechanical pump [mechanicalpump OP]. Here, the mechanical pump is a hydraulic pump driven by asource of vehicle driving force. With such a structure, the dischargeperformance of the pump is more easily ensured than with the structureof JP 2011-105192 A. Therefore, there is less necessity of thecountermeasure of covering the insufficiency in the dischargeperformance of the pump by increasing the number or diameter of thefriction plates. However, with the structure described in JP 2010-196867A, the distance from the hydraulic unit to a servo oil chamber[hydraulic pressure chamber 53] of the engagement device is likely to belong, and thus, the engagement device could deteriorate in response andcontrollability.

SUMMARY OF THE INVENTION

Therefore, it is desired to realize a vehicle drive device that easilyensures response and controllability of an engagement device whilesuppressing the engagement device from increasing in size.

According to an aspect of the present invention, a vehicle drive deviceincludes an input member drivingly connected to an internal combustionengine; a rotary electric machine; a speed change mechanism drivinglyconnected to the rotary electric machine; an output member drivinglyconnected to the speed change mechanism and wheels; an engagement devicecapable of changing a state of engagement between the input member andthe speed change mechanism; a hydraulic pump that discharges oil bybeing driven by the internal combustion engine or the rotary electricmachine; a first hydraulic pressure control device that controlshydraulic pressure supplied from the hydraulic pump and supplies thecontrolled hydraulic pressure to the speed change mechanism; a secondhydraulic pressure control device that is provided separately from thefirst hydraulic pressure control device and that controls the hydraulicpressure supplied from the hydraulic pump and supplies the controlledhydraulic pressure to the engagement device; and a case that houses therotary electric machine, the speed change mechanism, the engagementdevice, and the hydraulic pump. According to the aspect of the presentinvention, at least the engagement device is housed in a first housingspace formed by the case, and the second hydraulic pressure controldevice is provided at a part of the case forming the first housingspace.

In the present application, the term “drivingly connected” refers to astate in which two rotational elements are connected so as to be capableof transmitting driving force, and is used as a concept including astate in which the two rotational elements are connected so as to rotateas a unit with each other, or a state in which the two rotationalelements are connected so as to be capable of transmitting the drivingforce via one or two or more transmitting members. Such transmittingmembers include various members that transmit rotation at the same speedor at a changed speed, such as shafts, gear mechanisms, belts, andchains. Such transmitting members may also include engagement devicesthat selectively transmit the rotation and the driving force, such asfriction engagement device and meshing type engagement devices.

In addition, in the present application, the term “rotary electricmachine” is used as a concept including all of a motor (electric motor),a generator (electric generator), and a motor-generator that serves as amotor or a generator depending on the necessity.

According to the aspect, the hydraulic pressure supplied from thehydraulic pump can be controlled by the second hydraulic pressurecontrol device, and the controlled hydraulic pressure can be supplied tothe engagement device. Here, the hydraulic pump is driven by theinternal combustion engine or the rotary electric machine serving as asource of vehicle driving force, and thus, the discharge performance ofsuch a hydraulic pump is ensured relatively easily. Accordingly, theengagement device can be suppressed from increasing in size due toinsufficient discharge performance of the hydraulic pump.

According to the aspect, the second hydraulic pressure control devicethat supplies the hydraulic pressure to the engagement device isprovided at the part of the case forming the first housing space thathouses the engagement device. Accordingly, the distance between theengagement device and the second hydraulic pressure control device issmall, and thus, response and controllability of the engagement deviceis easily ensured.

Here, the vehicle drive device according to the present invention may bestructured such that the rotary electric machine is housed in the firsthousing space, and the second hydraulic pressure control device isarranged in a position having a portion overlapping with the rotaryelectric machine when viewed in a radial direction of the rotaryelectric machine.

In the present application, the expression like “having a portionoverlapping when viewed in a predetermined direction” indicates that,when the predetermined direction is assumed as a direction of line ofsight, and a viewing point is moved in various directions perpendicularto the direction of line of sight, at least some area includes theviewing point from which two members look overlapping with each other.

According to this structure, the length in the axial direction of aspace occupied by the second hydraulic pressure control device and therotary electric machine can be reduced by an amount of overlaptherebetween when viewed in the radial direction. Thus, the overalldevice can be downsized in the axial direction thereof. In addition, thestructure of the case can be more simplified than in the case ofproviding an electric machine housing space for housing the rotaryelectric machine separately from the first housing space.

The vehicle drive device according to the present invention may also bestructured such that the second hydraulic pressure control device isarranged in a position having a portion overlapping with the engagementdevice when viewed in a radial direction of the engagement device.

According to this structure, the engagement device can be arranged nearthe second hydraulic pressure control device that supplies the hydraulicpressure to the engagement device. Accordingly, the distance between theengagement device and the second hydraulic pressure control device issuppressed to be small, and thus, response and controllability of theengagement device is easily ensured.

The vehicle drive device according to the present invention may also bestructured such that the second hydraulic pressure control deviceincludes a solenoid valve that controls at least the hydraulic pressuresupplied to the engagement device and a valve body provided with an oilpassage that communicates with the solenoid valve.

According to this structure, the second hydraulic pressure controldevice is easily structured as an integrated component, and thus, anassembly process can be simplified.

The vehicle drive device according to the present invention may also bestructured such that the second hydraulic pressure control device ishoused in a second housing space formed separately from the firsthousing space by the case, and be structured to further include acommunicating oil passage through which the first housing spacecommunicates with the second housing space.

According to this structure, oil discharged from an oil discharge portof the second hydraulic pressure control device can be fed to the firsthousing space via the communicating oil passage. Thereby, the hydraulicpressure in the second housing space can be suppressed from risingrapidly due to the pressure (discharge pressure) of the oil dischargedfrom the oil discharge port of the second hydraulic pressure controldevice, and thus, the second hydraulic pressure control device can besuppressed from deteriorating in controllability when the oil isdischarged from the discharge port. Note that the space thatcommunicates with the second housing space via the communicating oilpassage is the first housing space formed by the part of the case inwhich the second hydraulic pressure control device is provided.Accordingly, the length of the communicating oil passage is small, andthus, the flow resistance of oil in the communicating oil passage iseasily suppressed to be small.

The vehicle drive device according to the present invention may also bestructured such that the rotary electric machine is housed in the firsthousing space and the speed change mechanism is housed in a speed changemechanism housing space formed by the case, such that the rotaryelectric machine is supplied with oil from the hydraulic pump, and suchthat the speed change mechanism housing space is provided therebelowwith a first oil retaining portion that communicates with the speedchange mechanism housing space and is capable of retaining oil, and thefirst housing space is provided therebelow with a second oil retainingportion that communicates with the first housing space and an oildischarge port of the second hydraulic pressure control device and iscapable of retaining oil, and be structured to further include adischarge oil passage that discharges oil in the second oil retainingportion to the first oil retaining portion.

According to this structure, both of the oil supplied to the rotaryelectric machine and the oil discharged from the oil discharge port ofthe second hydraulic pressure control device can be recovered into thesecond oil retaining portion, and these oils can be together dischargedto the first oil retaining portion via the discharge oil passage.Accordingly, the structure of the oil passage can be more simplified soas to discharge the oil more efficiently to the first oil retainingportion than in the case of discharging the oil supplied to the rotaryelectric machine and the oil discharged from the oil discharge port ofthe second hydraulic pressure control device to the first oil retainingportion via respective separate oil passages. As a result, theproduction cost of the device can be reduced, and the overall device canbe downsized.

The vehicle drive device according to the present invention may also bestructured such that the rotary electric machine is housed in the firsthousing space and the speed change mechanism is housed in the speedchange mechanism housing space formed by the case, and the case isstructured to be separable into a first case portion forming the firsthousing space and a second case portion forming the speed changemechanism housing space, and such that the second hydraulic pressurecontrol device is provided in the first case portion.

According to this structure, most of the portion on the speed changemechanism side can be used commonly by a drive device provided with arotary electric machine and a drive device not provided with a rotaryelectric machine, and thus, the production cost can be suppressed.

The vehicle drive device according to the present invention may bestructured such that the second hydraulic pressure control device isprovided at a lower portion of the first case portion in the structurein which the second hydraulic pressure control device is provided in thefirst case portion as described above.

According to this structure, the second hydraulic pressure controldevice can be arranged while satisfying conditions on mountablity to avehicle.

The vehicle drive device of each of the above-described structures maybe structured such that the rotary electric machine and the speed changemechanism are drivingly connected to each other via a fluid couplingprovided with a coupling input side member drivingly connected to therotary electric machine and a coupling output side member drivinglyconnected to the speed change mechanism, such that the engagement deviceis capable of changing a state of engagement between the input memberand the coupling input side member, and such that the first hydraulicpressure control device controls the hydraulic pressure supplied fromthe hydraulic pump and supplies the controlled hydraulic pressure to thefluid coupling.

In the present application, the term “fluid coupling” is used as aconcept including both of a torque converter having a torque amplifyingfunction and an ordinary fluid coupling having no torque amplifyingfunction.

According to this structure, it is possible to appropriately realize avehicle drive device provided with a fluid coupling.

The vehicle drive device according to the present invention may also bestructured such that the rotary electric machine, the fluid coupling,and the engagement device are arranged on a first axial direction side,that is, on one side in an axial direction of the speed changemechanism, relative to the speed change mechanism, and arranged in theorder of the rotary electric machine, the fluid coupling, and the speedchange mechanism from the first axial direction side toward an oppositeside thereof, and such that the engagement device is arranged in aposition having a portion overlapping with the rotary electric machinewhen viewed in the radial direction of the rotary electric machine.

According to this structure, it is easier to suppress to be small thedistance between the second hydraulic pressure control device and theengagement device to be supplied with the hydraulic pressure from thesecond hydraulic pressure control device, while suppressing thedistances to be small from the first hydraulic pressure control deviceto the fluid coupling and the speed change mechanism that are to besupplied with the hydraulic pressure from the first hydraulic pressurecontrol device, than in the case of arranging those members in the orderof the fluid coupling, the rotary electric machine, and the speed changemechanism from the first axial direction side toward the opposite sidethereof. Accordingly, for the members to be supplied with the hydraulicpressure, response and controllability are easily ensured, andperformance to supply the hydraulic pressure is easily ensured.

The vehicle drive device according to the present invention may also bestructured such that the rotary electric machine is housed in the firsthousing space, such that the fluid coupling is housed in a fluidcoupling housing space formed by the case, such that the speed changemechanism is housed in the speed change mechanism housing space formedby the case, and such that the first housing space, the speed changemechanism housing space, and the fluid coupling housing space are formedas spaces independent from one another.

According to this structure, even when the rotary electric machine andthe speed change mechanism are supplied with oil for cooling or oil forlubrication, the fluid coupling housing space can be a space in which nooil is present around the fluid coupling, and thus, drag loss of oil canbe suppressed from occurring when the fluid coupling rotates.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing an outline structure of a vehicledrive device according to an embodiment of the present invention;

FIG. 2 is a partial cross-sectional view of the vehicle drive deviceaccording to the embodiment of the present invention;

FIG. 3 is an enlarged view of a part of FIG. 2;

FIG. 4 is an enlarged view of a part of FIG. 2;

FIG. 5 is a partial cross-sectional view of the vehicle drive deviceaccording to the embodiment of the present invention, taken at alocation different from that of FIG. 2; and

FIG. 6 is a diagram showing an outline structure of a hydraulic controlsystem of a second hydraulic pressure control device according to theembodiment of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

An embodiment of a vehicle drive device according to the presentinvention will be described with reference to the accompanying drawings.In the following description, unless particularly specified, an “axialdirection L”, a “radial direction R”, and a “circumferential direction”are defined with reference to a shaft center (shaft center X shown inFIG. 2) of an input shaft of a speed change mechanism TM (a speed changeinput shaft, that is an intermediate shaft M in the present example). Inthe present embodiment, a rotary electric machine MG a first clutch C1,and a torque converter TC are all arranged on the same axis as that ofthe speed change mechanism TM. Accordingly, an “axial direction”, a“radial direction”, and a “circumferential direction” of each of therotary electric machine MG the first clutch C1, and the torque converterTC coincide with the “axial direction L”, the “radial direction R”, andthe “circumferential direction”, respectively, of the speed changemechanism TM. A “first axial direction L1” represents a direction froman output shaft of the speed change mechanism TM (a speed change outputshaft, that is, an output shaft O in the present embodiment) toward thespeed change input shaft (leftward in FIG. 2) along the axial directionL, and a “second axial direction L2” represents an opposite direction tothe first axial direction L1 (rightward in FIG. 2). In addition, a“radially inward direction R1” represents an inward direction along theradial direction R while a “radially outward direction R2” represents anoutward direction along the radial direction R.

In the following description, the expressions such as “up/upper/above”and “down/lower/below” are defined with reference to a verticaldirection V (refer to FIG. 2) in the state in which a vehicle drivedevice 1 is mounted on a vehicle (vehicle-mounted state). The expressionsuch as “up”, “upper”, or “above” represents the upper side in FIG. 2while the expression such as “down”, “lower”, or “below” represents thelower side in FIG. 2. A direction with respect to each member representsa direction in the state in which the member is assembled to the vehicledrive device 1. Each term regarding the direction, position, or the likewith respect to each member is used as a concept including a state ofhaving a difference due to an allowable error in manufacturing.

1. Overall Structure of Vehicle Drive Device

FIG. 1 is a schematic diagram showing an outline structure of thevehicle drive device 1 according to the present embodiment. As shown inFIG. 1, the vehicle drive device 1 is provided with an input shaft Idrivingly connected to an internal combustion engine E, the rotaryelectric machine MG; the torque converter TC, the speed change mechanismTM, the output shaft O drivingly connected to the speed change mechanismTM and wheels W, and a case 3. The torque converter TC is provided witha coupling input side member 2 drivingly connected to the rotaryelectric machine MG and a coupling output side member 4 paired with thecoupling input side member 2. The speed change mechanism TM is drivinglyconnected to the coupling output side member 4 via the intermediateshaft M. That is, in the present embodiment, the speed change mechanismTM is drivingly connected to the rotary electric machine MG via thetorque converter TC. The vehicle drive device 1 is further provided withthe first clutch C1 that is capable of changing the state of engagementbetween the input shaft I and the speed change mechanism TM. In thepresent embodiment, the rotary electric machine MG and the speed changemechanism TM are drivingly connected to each other via the torqueconverter TC, and the first clutch C1 changes the state of engagementbetween the input shaft I and the speed change mechanism TM by changingthe state of engagement between the input shaft I and the coupling inputside member 2. The members are arranged along a power transmission pathbetween the input shaft I and the output shaft O, as shown in FIG. 1,from the side of the input shaft I in the order of the first clutch C1,the rotary electric machine MG; the torque converter TC, and the speedchange mechanism TM. In the present embodiment, the input shaft I andthe output shaft O correspond to an “input member” and an “outputmember”, respectively, in the present invention. In the presentembodiment, the first clutch C1 and the torque converter TC correspondto an “engagement device” and a “fluid coupling”, respectively, in thepresent invention.

The internal combustion engine E is a motor to take out power by beingdriven by combustion of fuel inside the engine. For example, a gasolineengine or a diesel engine can be used as the internal combustion engineE. In the present embodiment, the input shaft I is drivingly connectedto an output shaft (such as a crankshaft) of the internal combustionengine E via a damper 16 (refer to FIG. 2 although omitted in FIG. 1).The input shaft I can also be structured to be drivingly connected tothe output shaft of the internal combustion engine E not through thedamper 16. The input shaft I can also be structured to be provided as aunit with either one (such as the output shaft of the internalcombustion engine E) of the two members to be drivingly connected to, orcan be structured to be provided as a separate body from both of the twomembers.

The first clutch C1 is provided between the input shaft I and the rotaryelectric machine MG (a rotor member 21) in the power transmission path,and serves as an internal combustion engine cut-off clutch thatdisconnects the internal combustion engine E from the wheels W. Thespeed change mechanism TM is composed of a mechanism that is capable ofchanging a speed ratio in a stepwise manner or in a stepless manner(such as an automatic stepped speed change mechanism). The speed changemechanism TM changes a rotational speed of the intermediate shaft M(speed change input shaft) drivingly connected to the coupling outputside member 4 at a predetermined speed ratio, and transmits the changedspeed to the output shaft O (speed change output shaft) drivinglyconnected to a differential gear unit DF for output.

The output shaft O is drivingly connected to the wheels W via thedifferential gear unit DF for output. The rotation and torquetransmitted to the output shaft O are distributed and transmitted, viathe differential gear unit DF for output, to the two right and leftwheels W. Thereby, the vehicle drive device 1 can run the vehicle bytransmitting the torque of one or both of the internal combustion engineE and the rotary electric machine MG. That is, the vehicle drive device1 is structured as a drive device for a hybrid vehicle, andspecifically, structured as a one-motor parallel type hybrid drivedevice. The output shaft O can also be structured to be provided as aunit with either one (such as a drive shaft) of the two members to bedrivingly connected to, or can be structured to be provided as aseparate body from both of the two members.

In the present embodiment, all of the input shaft I, the first clutchC1, the rotary electric machine MG the torque converter TC, theintermediate shaft M, the speed change mechanism TM, and the outputshaft O are arranged on the shaft center X (refer to FIG. 2), and thevehicle drive device 1 according to the present embodiment has asingle-axis structure suitable for being mounted on a vehicle of an FR(front engine, rear drive) type.

2. Structures of Various Parts of Vehicle Drive Device

Next, structures of various parts of the vehicle drive device 1according to the present embodiment will be described with reference toFIGS. 2 to 5. FIG. 2 is a cross-sectional view taken by cutting a partof the vehicle drive device 1 according to the present embodiment alonga vertical plane including the shaft center X. FIGS. 3 and 4 areenlarged views of parts of FIG. 2. FIG. 5 is a cross-sectional viewtaken by cutting a part of the vehicle drive device 1 according to thepresent embodiment along a vertical plane in parallel with the shaftcenter X at a location different in the horizontal direction from thatof FIG. 2. FIGS. 2 and 3 omit to show a specific structure of the speedchange mechanism TM.

2-1. Rotary Electric Machine

As shown in FIG. 2, the rotary electric machine MG is provided with astator St and the rotor member 21. The stator St is fixed to the case 3and is provided with coil end portions Ce at both ends in the axialdirection L thereof. As shown in FIG. 3, the rotor member 21 is providedwith a rotor Ro arranged in a manner opposed to the stator St and arotor support member 22 that rotatably supports the rotor Ro relative tothe case 3. In the present embodiment, the rotor Ro is arranged on theradially inward direction R1 side of the stator St, and the rotorsupport member 22 is formed so as to extend in the radially inwarddirection R1 from the rotor Ro and supports the rotor Ro from theradially inward direction R1 side.

In the present embodiment, as shown in FIGS. 3 and 4, the rotor supportmember 22 is provided with a rotor holding portion 25 that holds therotor Ro and with a radially extending portion 26. The rotor holdingportion 25 is formed in a cylindrical shape having an outercircumferential portion in contact with an inner circumferential surfaceof the rotor Ro and having a flange portion in contact with a side facein the axial direction L of the rotor Ro. The radially extending portion26 is formed in an annular plate shape that extends in the radiallyinward direction R1 from a portion on the second axial direction L2 siderelative to a central portion in the axial direction L of the rotorholding portion 25. The radially extending portion 26 is provided, at anend in the radially inward direction R1 thereof, with a first axiallyprojecting portion 23 that is a cylindrical projecting portionprojecting in the second axial direction L2 and with a second axiallyprojecting portion 24 that is a cylindrical projecting portionprojecting in the first axial direction L1. The first axially projectingportion 23 serves as a supported portion that is rotatably supported inthe radial direction R by a bearing 96 relative to the case 3(specifically, a second support wall 32 to be described later). Thesecond axially projecting portion 24 constitutes a connecting portionwith a connecting member 10 to be described later.

A plate-shaped member 27 having an annular plate shape is mounted on therotor support member 22 so as to rotate as a unit therewith. Theplate-shaped member 27 is mounted on the first axial direction L1 siderelative to the central portion in the axial direction L of the rotorholding portion 25. Thereby, on the radially inward direction R1 side ofthe rotor holding portion 25, a space is formed that is partitioned offby the rotor holding portion 25 on the radially outward direction R2side and partitioned off by the radially extending portion 26 and theplate-shaped member 27 on both sides in the axial direction L. Thisspace is provided as a space partitioned off so as to be oil-tight usingseal members or the like appropriately arranged at various parts, and isformed therein with an operating oil pressure chamber H1 and acirculating oil pressure chamber H2 of the first clutch C1 to bedescribed later.

2-2. First Clutch

The first clutch C1 is an engagement device that is capable of changingthe state of engagement by being operated by hydraulic pressure. Thefirst clutch C1 is structured so as to be capable of changing the stateof engagement of two engagement members engaged by the first clutch C1between a state in which the two engagement members are engaged witheach other (including a slip-engaged state) and a state in which the twoengagement members are not engaged with each other (a released state).Driving force is transmitted between the input shaft I and the rotormember 21 in the state in which the two engagement members are engagedwith each other, while the driving force is not transmitted between theinput shaft I and the rotor member 21 in the state in which the twoengagement members are released from each other.

As shown in FIGS. 3 and 4, the first clutch C1 is arranged in theoil-tight space that is partitioned off by the rotor holding portion 25on the radially outward direction R2 side and partitioned off by theradially extending portion 26 and the plate-shaped member 27 on bothsides in the axial direction L. With this arrangement, the first clutchC1 is arranged in a position having a portion overlapping with therotary electric machine MG when viewed in the radial direction of therotary electric machine MG (in the present example, in the samedirection as the radial direction R). Specifically, the first clutch C1is arranged on the radially inward direction R1 side relative to therotor Ro and in a position overlapping with the central portion area inthe axial direction L of the rotor Ro when viewed in the radialdirection R.

In the present embodiment, the first clutch C1 is structured as awet-type multi-plate clutch mechanism. Specifically, the first clutch C1is provided with a clutch hub 51, friction members 53, a piston 54, andan urging member 55, and these members are all arranged in positionseach having a portion overlapping with the rotor Ro when viewed in theradial direction R. In the present example, the rotor holding portion 25of the rotor support member 22 serves as a clutch drum. The first clutchC1 has, as the friction members 53, input-side friction members andoutput-side friction members serving as respective pairs. The input-sidefriction members are supported from the radially inward direction R1side by an outer circumferential portion of the clutch hub 51, while theoutput-side friction members are supported from the radially outwarddirection R2 side by an inner circumferential portion of the rotorholding portion 25. The clutch hub 51 is connected, at an end in theradially inward direction R1 thereof, to a flange portion Ia of theinput shaft I.

As shown in FIG. 4, the operating oil pressure chamber H1 of the firstclutch C1 is formed by being surrounded by the radially extendingportion 26 and the second axially projecting portion 24 of the rotorsupport member 22 and by the piston 54. The circulating oil pressurechamber H2 of the first clutch C1 is formed by mainly being surroundedby the rotor holding portion 25 (clutch drum) of the rotor supportmember 22, the plate-shaped member 27 mounted on the rotor supportmember 22, and the piston 54, and houses therein the clutch hub 51 andthe friction members 53. The operating oil pressure chamber H1 and thecirculating oil pressure chamber H2 are arranged separately on bothsides in the axial direction L relative to the piston 54, andpartitioned off from each other so as to be oil-tight using the sealmembers. In the present embodiment, both of the operating oil pressurechamber H1 and the circulating oil pressure chamber H2 are arranged onthe radially inward direction R1 side relative to the rotor Ro and inpositions overlapping, over the whole areas in the axial direction Lthereof, with the rotor Ro when viewed in the radial direction R.

The urging member 55 presses the piston 54 toward the friction members53 in the axial direction L (in the present example, in the first axialdirection L1). Thereby, the first clutch C1 is engaged or releasedaccording to a balance between the pressing force of the piston 54 inthe first axial direction L1 by the hydraulic pressure in the operatingoil pressure chamber H1 and the urging member 55 and the pressing forceof the piston 54 in the second axial direction L2 by the hydraulicpressure in the circulating oil pressure chamber H2. That is, in thepresent embodiment, the piston 54 is slid along the axial direction Ldepending on the difference in hydraulic pressure (differentialpressure) between the operating oil pressure chamber H1 and thecirculating oil pressure chamber H2, and thus, the state of engagementof the first clutch C1 can be controlled. While the vehicle is running,the circulating oil pressure chamber H2 is basically filled with oil ata predetermined pressure or higher, and the oil cools the frictionmembers 53.

2-3. Torque Converter

The torque converter TC is provided with the coupling input side member2 that is drivingly connected to the rotor member 21 of the rotaryelectric machine MG and with the coupling output side member 4 that ispaired with the coupling input side member 2 and drivingly connected tothe wheels W. Specifically, as shown in FIG. 2, the torque converter TCis provided with a pump impeller 61, a turbine runner 62, a secondclutch C2 serving as a lock-up clutch, and a cover portion 63 housingthese parts. The cover portion 63 is connected so as to rotate as a unitwith the pump impeller 61 that is arranged inside thereof, and alsoconnected so as to rotate as a unit with a pump drive shaft 67 to bedescribed later. In the present embodiment, the coupling input sidemember 2 is composed of the pump impeller 61, the cover portion 63, andthe pump drive shaft 67. The coupling output side member 4 is composedof the turbine runner 62, which in turn is connected (in the presentexample, connected via splines) to the intermediate shaft M. Thereby, asshown in FIG. 1, the coupling output side member 4 is drivinglyconnected to the wheels W via the intermediate shaft M, the speed changemechanism TM, the output shaft O, and the differential gear unit DF foroutput.

In the present embodiment, the coupling input side member 2 isconnected, via the connecting member 10, to the rotor member 21 so as torotate as a unit with each other. Although details will be describedlater, the second support wall 32 of the case 3 is formed with a tubularprojecting portion 32 a as shown in FIG. 4. The connecting member 10 hasa tubular axially extending portion that extends in the axial directionL through the side in the radially inward direction R1 of the tubularprojecting portion 32 a and an annular plate-shaped radially extendingportion that extends in the radial direction R on the first axialdirection L1 side relative to the tubular projecting portion 32 a. Thecover portion 63 constituting the coupling input side member 2 isconnected via splines to the axially extending portion of the connectingmember 10, and the cover portion 63 and the connecting member 10 arefixed to each other so as to be relatively immovable in the axialdirection by using a fastening member 90. The second axially projectingportion 24 of the rotor member 21 is connected so as to rotate as a unitwith the radially extending portion of the connecting member 10 in astate relatively movable in the axial direction L. Thereby, the couplinginput side member 2 and the rotor member 21 are drivingly connected soas to rotate as a unit with each other.

2-4. Case

The case 3 houses the rotary electric machine MG the torque converterTC, the speed change mechanism TM, and the first clutch C1. In thepresent embodiment, as shown in FIG. 2, the case 3 is provided with afirst support wall 31, the second support wall 32, a third support wall33, and a peripheral wall 34. The peripheral wall 34 is formed into agenerally cylindrical shape covering an outer periphery of the rotaryelectric machine MG the first clutch C1, the torque converter TC, thespeed change mechanism TM, and the like. The first support wall 31, thesecond support wall 32, and the third support wall 33 are arranged inthe listed order from the first axial direction L1 side so as topartition off, in the axial direction L, a space in the case formed inthe radially inward direction R1 of the peripheral wall 34.

As shown in FIG. 2, the case 3 is formed with a first housing space S1that houses at least the first clutch C1, a rotary electric machinehousing space SG that houses the rotary electric machine MG a fluidcoupling housing space SC that houses the torque converter TC, and aspeed change mechanism housing space SM that houses the speed changemechanism TM. In the present embodiment, the first housing space S1 andthe rotary electric machine housing space SG are formed as the samespace. That is, in the present embodiment, the rotary electric machineMG can be said to be housed in the first housing space S1. The rotaryelectric machine housing space SG (first housing space S1), the fluidcoupling housing space SC, and the speed change mechanism housing spaceSM are formed in the listed order from the first axial direction L1side. Thereby, in the present embodiment, the rotary electric machine MGand the first clutch C1, the torque converter TC, and the speed changemechanism TM are arranged in this order in the second axial direction L2from the first axial direction L1 side. That is, the rotary electricmachine MG the first clutch C1, and the torque converter TC are arrangedon the first axial direction L1 side relative to the speed changemechanism TM. The rotary electric machine housing space SG (firsthousing space S1), the fluid coupling housing space SC, and the speedchange mechanism housing space SM are also formed as spaces independentfrom one another. Here, the expression “spaces independent from oneanother” means that the spaces are partitioned off from one another soas to be oil-tight. Such a structure is achieved by appropriatelyarranging seal members at various parts.

The rotary electric machine housing space SG the fluid coupling housingspace SC, and the speed change mechanism housing space SM are all formedas annular spaces. Specifically, the rotary electric machine housingspace SG is formed between the first support wall 31 and the secondsupport wall 32 in the axial direction L. The fluid coupling housingspace SC is formed between the second support wall 32 and the thirdsupport wall 33 in the axial direction L. The speed change mechanismhousing space SM is formed between the third support wall 33 and asupport wall (not shown) arranged on the second axial direction L2 siderelative to the third support wall 33 in the axial direction L. Therotary electric machine housing space SG the fluid coupling housingspace SC, and the speed change mechanism housing space SM are allpartitioned off by the peripheral wall 34 on the second axial directionL2 side. The damper 16 is housed in a space on the first axial directionL1 side relative to the first support wall 31 in the case 3.

The first housing space S1 communicates with a second housing space S2to be described later via a first communicating oil passage AC. In thepresent embodiment, the rotary electric machine housing space SG and thesecond housing space S2 communicate with each other via the firstcommunicating oil passage AC because the first housing space S1 and therotary electric machine housing space SG are formed as the same space inthe present embodiment, as described above.

In the present embodiment, as shown in FIG. 2, the case 3 is structuredto be separable into a first case portion 3 a and a second case portion3 b arranged on the second axial direction L2 side relative to the firstcase portion 3 a. The first case portion 3 a and the second case portion3 b are connected to each other at a joint portion 5. In the presentembodiment, they are fastened to each other at respective portions ofthe peripheral wall 34 by fastener bolts (not shown). In the followingdescription, a portion of the peripheral wall 34 constituted by thefirst case portion 3 a will be called a first peripheral wall 34 a whilea portion of the peripheral wall 34 constituted by the second caseportion 3 b will be called a second peripheral wall 34 b.

The first case portion 3 a is a portion that forms the first housingspace S1. In the present embodiment, the first case portion 3 a is alsoa portion that forms the rotary electric machine housing space SG.Specifically, the first case portion 3 a has the first support wall 31and the second support wall 32, and the first housing space S1 (rotaryelectric machine housing space SG) is formed by only the first caseportion 3 a. In the present embodiment, the first case portion 3 afurther forms a housing space for the damper 16. The second case portion3 b is a portion that forms the speed change mechanism housing space SM.Specifically, the second case portion 3 b has the third support wall 33,and the speed change mechanism housing space SM is formed by only thesecond case portion 3 b. The first case portion 3 a and the second caseportion 3 b cooperate to form the fluid coupling housing space SC in anarea including, in the axial direction L, the joint portion 5 of thefirst case portion 3 a and the second case portion 3 b.

2-4-1. First Support Wall

The first support wall 31 is formed, as shown in FIG. 2, so as to extendin the radial direction R and the circumferential direction on the firstaxial direction L1 side relative to the rotary electric machine MG (inthe present example, between the rotary electric machine MG and thedamper 16 in the axial direction L). A through-hole is formed so as toextend in the axial direction L in the central portion in the radialdirection R of the first support wall 31 that is formed in a disc shape,and the input shaft I is inserted in this through-hole. The firstsupport wall 31 is formed such that a portion on the radially inwarddirection R1 side thereof is offset as a whole in the axial direction Lso as to be located on the second axial direction L2 side relative to aportion on the radially outward direction R2 side thereof.

2-4-2. Second Support Wall

The second support wall 32 is formed, as shown in FIG. 2, so as toextend in the radial direction R and the circumferential directionbetween the rotary electric machine MG and the torque converter TC inthe axial direction L. A through-hole passing through in the axialdirection L is formed in the central portion in the radial direction Rof the second support wall 32 that is formed in a disc shape, and theconnecting member 10 is arranged in this through-hole. The couplinginput side member 2 arranged on the second axial direction L2 siderelative to the second support wall 32 is drivingly connected so as torotate as a unit with the rotor member 21 arranged on the first axialdirection L1 side via the connecting member 10.

The second support wall 32 is formed such that a portion on the radiallyinward direction R1 side thereof is offset as a whole in the axialdirection L so as to be located on the first axial direction L1 siderelative to a portion on the radially outward direction R2 side thereof.As shown in FIG. 4, an end on the radially inward direction R1 side ofthe second support wall 32 is formed with the tubular projecting portion32 a that projects in the first axial direction L1, and thus, the secondsupport wall 32 has a thick-walled portion (boss) having a predeterminedthickness in the axial direction L at the end on the radially inwarddirection R1 side. The tubular projecting portion 32 a is arranged onthe radially inward direction R1 side relative to the rotor member 21and in a position having a portion overlapping with the rotor member 21when viewed in the radial direction R.

A first oil passage A1 and a second oil passage A2 are formed inside thesecond support wall 32. As shown in FIGS. 3 and 4, the first oil passageA1 communicates with the operating oil pressure chamber H1 of the firstclutch C1, and serves as an oil supply passage for supplying oil foroperating the piston 54 to the operating oil pressure chamber H1. Asshown in FIG. 4, the second oil passage A2 communicates with thecirculating oil pressure chamber H2 of the first clutch C1, and servesas an oil supply passage for supplying oil for cooling the frictionmembers 53 to the circulating oil pressure chamber H2. As shown in FIG.4, the first oil passage A1 extends in the first axial direction L1inside the tubular projecting portion 32 a, and then, communicates withthe operating oil pressure chamber H1 via a communication hole 32 cformed in the tubular projecting portion 32 a, a through-hole 94 cformed in a sleeve member 94, and a through-hole 24 c formed in thesecond axially projecting portion 24 of the rotor support member 22.Here, the sleeve member 94 is provided for restricting the oil fromflowing in the axial direction L through a gap in the radial directionbetween an outer circumferential surface of the tubular projectingportion 32 a and an inner circumferential surface of the second axiallyprojecting portion 24.

As shown in FIG. 4, the second oil passage A2 is formed so as to extendin the first axial direction L1 inside the tubular projecting portion 32a, and then to open at an end face on the first axial direction L1 sideof the tubular projecting portion 32 a. The opening of the second oilpassage A2 opens to a gap formed and extending in the axial direction Lbetween the connecting member 10 and the tubular projecting portion 32a. A connecting portion of the second axially projecting portion 24 withthe connecting member 10 is formed with a gap that passes in the radialdirection R through the second axially projecting portion 24. The secondoil passage A2 communicates with the circulating oil pressure chamber H2via these two gaps.

2-4-3. Third Support Wall

The third support wall 33 is formed, as shown in FIG. 2, so as to extendin the radial direction R and the circumferential direction on thesecond axial direction L2 side relative to the torque converter TC (inthe present example, between the torque converter TC and the speedchange mechanism TM in the axial direction L). A through-hole is formedso as to extend in the axial direction L in the central portion in theradial direction R of the third support wall 33 that is formed in a discshape, and the intermediate shaft M is inserted in this through-hole.The third support wall 33 is provided with a hydraulic pump 9 thatgenerates hydraulic pressure for supplying oil to various parts of thevehicle drive device 1. Specifically, the third support wall 33 has afirst portion that is fixed to the peripheral wall 34 (specifically, thesecond peripheral wall 34 b) and a second portion that is mounted on anend face on the first axial direction L1 side of the first portion, anda pump chamber of the hydraulic pump 9 is formed in a space partitionedoff by the first portion and the second portion on both sides in theaxial direction L. Moreover, the third support wall 33 is formed thereinwith a suction oil passage (not shown) and a discharge oil passage AB ofthe hydraulic pump 9.

As described above, the pump drive shaft 67 driving the hydraulic pump 9is drivingly connected so as to rotate as a unit with the pump impeller61 of the torque converter TC. The pump impeller 61 is drivinglyconnected, as shown in FIG. 1, to the rotary electric machine MG and theinternal combustion engine E. Accordingly, the hydraulic pump 9 isdriven by the internal combustion engine E or the rotary electricmachine MG serving as a source of driving force of the wheels W, andthereby discharges oil. The hydraulic pressure generated by thehydraulic pump 9 is controlled by a first hydraulic pressure controldevice 81 to be described later, and the controlled hydraulic pressureis supplied to the torque converter TC and the speed change mechanismTM. The hydraulic pressure generated by the hydraulic pump 9 is alsocontrolled by a second hydraulic pressure control device 82 to bedescribed later, and the controlled hydraulic pressure is supplied tothe first clutch C1.

3. Supply Structure of Hydraulic Pressure

Next, a supply structure of hydraulic pressure in the vehicle drivedevice 1 according to the present embodiment will be described. Thevehicle drive device 1 is provided with the first hydraulic pressurecontrol device 81 as a hydraulic pressure control device for controllingthe hydraulic pressure supplied from the hydraulic pump 9, and is alsoprovided with the second hydraulic pressure control device 82 separatelyfrom the first hydraulic pressure control device 81.

3-1. First Hydraulic Pressure Control Device

The first hydraulic pressure control device 81 is a device that controlsthe hydraulic pressure supplied from the hydraulic pump 9 and suppliesthe controlled hydraulic pressure to the torque converter TC and thespeed change mechanism TM. As shown in FIG. 2, in the presentembodiment, the first hydraulic pressure control device 81 is providedat the second case portion 3 b, and in the present example, provided ata lower portion of the second case portion 3 b. Specifically, the firsthydraulic pressure control device 81 is fixed to an outercircumferential portion (in the present example, to a portion having adownward facing surface in the outer circumferential portion) of thesecond peripheral wall 34 b of the second case portion 3 b. In thepresent embodiment, the first hydraulic pressure control device 81 isarranged in a position having a portion overlapping with the speedchange mechanism TM when viewed in the radial direction R which is theradial direction of the speed change mechanism TM. In the presentexample, although not shown, the first hydraulic pressure control device81 is arranged in a position overlapping, over the whole area in theaxial direction L thereof, with the speed change mechanism TM whenviewed in the radial direction R.

Specifically, the case 3 is provided with a first oil pan 11 mounted toa lower portion of the second case portion 3 b, and a space surroundedby the second case portion 3 b and the first oil pan 11 serves as afirst hydraulic pressure control device housing space that houses thefirst hydraulic pressure control device 81. The first hydraulic pressurecontrol device housing space is formed in a position having a portionoverlapping with the speed change mechanism TM when viewed from below.The first hydraulic pressure control device 81 is arranged, while beinghoused in the first hydraulic pressure control device housing space, ina position having a portion overlapping with the speed change mechanismTM when viewed from below.

The first hydraulic pressure control device 81 is provided with aplurality of hydraulic pressure control valves and oil flow passages.The hydraulic pressure control valves provided in the first hydraulicpressure control device 81 include a speed change mechanism hydraulicpressure control valve (not shown) that controls hydraulic pressuresupplied to the speed change mechanism TM and a fluid coupling hydraulicpressure control valve (not shown) that controls hydraulic pressuresupplied to the torque converter TC. The hydraulic pressure supplied tothe speed change mechanism TM is used for controlling the state ofengagement of engagement devices provided in the speed change mechanismTM, and used also for lubricating and cooling gear mechanisms, bearings,and the like provided in the speed change mechanism TM. The hydraulicpressure supplied to the torque converter TC is used for transmittingpower in the torque converter TC, and is supplied to an operating oilpressure chamber of the second clutch C2 to be used for controlling thestate of engagement of the second clutch C2. The oil after beingsupplied to the speed change mechanism TM and the torque converter TC isreturned to the first oil pan 11 that is arranged below the speed changemechanism TM.

Although details are omitted, a circulation path of oil flowing throughthe hydraulic pump 9, the first hydraulic pressure control device 81,the torque converter TC, and the speed change mechanism TM is providedwith an oil cooler (heat exchanger) for cooling the oil in series or inparallel with the path. The oil cooler is provided in the second caseportion 3 b. For example, the circulation path can be structured suchthat the oil supplied to at least a heat-generating portion is returnedto the first oil pan 11 via the oil cooler, or such that the oil to besupplied to at least the heat-generating portion is supplied to placesto be supplied with the oil via the oil cooler.

As shown in FIG. 3, the oil recovered into the first oil pan 11 isretained in the above-mentioned first hydraulic pressure control devicehousing space. The first hydraulic pressure control device housing spaceis formed below the speed change mechanism housing space SM, andcommunicates with the speed change mechanism housing space SM via anopening formed in the second peripheral wall 34 b. Consequently, in thepresent embodiment, the first hydraulic pressure control device housingspace that is formed by being surrounded by the second case portion 3 band the first oil pan 11 constitutes a first oil retaining portion U1.The hydraulic pump 9 suctions the oil retained in the first oilretaining portion U1 and generates the hydraulic pressure.

Line pressure that is the discharge pressure (output pressure) of thehydraulic pump 9 is controlled by a line pressure control valve (notshown). For example, a pressure regulator valve is used as the linepressure control valve, and the line pressure is controlled based onreference pressure supplied to a reference pressure chamber. In thepresent embodiment, the line pressure control valve is provided in thefirst hydraulic pressure control device 81, and the pressure controlled(regulated) by the line pressure control valve is supplied to the secondhydraulic pressure control device 82 via a third oil passage A3.

3-2. Second Hydraulic Pressure Control Device

The second hydraulic pressure control device 82 is a device thatcontrols the hydraulic pressure supplied from the hydraulic pump 9 andsupplies the controlled hydraulic pressure to the first clutch C1. Asshown in FIG. 2, in the present embodiment, the second hydraulicpressure control device 82 is provided at the first case portion 3 a,and in the present example, provided at a lower portion of the firstcase portion 3 a. The first case portion 3 a is a portion that forms thefirst housing space S1, and the second hydraulic pressure control device82 is provided in the portion forming the first housing space S1 of thecase 3. That is, the second hydraulic pressure control device 82 isprovided at a position of the case 3 forming the first housing space S1.Specifically, the second hydraulic pressure control device 82 is fixedto an outer circumferential portion (in the present example, to aportion having a downward facing surface in the outer circumferentialportion) of the first peripheral wall 34 a of the first case portion 3a. The first case portion 3 a is arranged on the first axial directionL1 side relative to the second case portion 3 b that is provided withthe first hydraulic pressure control device 81. Consequently, in thepresent embodiment, the second hydraulic pressure control device 82 isarranged on the first axial direction L1 side relative to the firsthydraulic pressure control device 81. Specifically, the first hydraulicpressure control device 81 is arranged on the second axial direction L2side relative to the joint portion 5 of the first case portion 3 a andthe second case portion 3 b, while the second hydraulic pressure controldevice 82 is arranged on the first axial direction L1 side relative tothe joint portion 5. In addition, in the present embodiment, the secondhydraulic pressure control device 82 is arranged below an upper endportion of the first hydraulic pressure control device 81.

Specifically, the case 3 is provided with a second oil pan 12 mounted toa lower portion of the first case portion 3 a, and a space surrounded bythe first case portion 3 a and the second oil pan 12 serves as a secondhydraulic pressure control device housing space that houses the secondhydraulic pressure control device 82. That is, the second hydraulicpressure control device housing space is a space formed by the case 3separately from the first housing space S1, and constitutes the secondhousing space S2 that houses the second hydraulic pressure controldevice 82. The second housing space S2 is formed in a position having aportion overlapping with the rotary electric machine MG when viewed frombelow, and also is formed in a position having a portion overlappingwith the first clutch C1 when viewed from below. Note that the secondoil pan 12 is provided independently from the first oil pan 11. That is,the first oil pan 11 and the second oil pan 12 are composed of membersdifferent from each other, and are mounted at locations different fromeach other in the case 3. Specifically, the first oil pan 11 is arrangedon the second axial direction L2 side relative to the joint portion 5 ofthe first case portion 3 a and the second case portion 3 b, while thesecond oil pan 12 is arranged on the first axial direction L1 siderelative to the joint portion 5.

As shown in FIG. 3, the second hydraulic pressure control device 82 isarranged in a position having a portion overlapping with the rotaryelectric machine MG when viewed in the radial direction of the rotaryelectric machine MG (in the present example, in the same direction asthe radial direction R). In the present example, the second hydraulicpressure control device 82 is arranged toward the second axial directionL2 side relative to the rotary electric machine MG so that a portion onthe first axial direction L1 side of the second hydraulic pressurecontrol device 82 overlaps with the rotary electric machine MG(specifically, the stator St) when viewed in the radial direction R.Moreover, in the present embodiment, the second hydraulic pressurecontrol device 82 is arranged in a position having a portion overlappingwith the rotary electric machine MG when viewed from below.

Furthermore, as shown in FIG. 3, the second hydraulic pressure controldevice 82 is arranged in a position having a portion overlapping withthe first clutch C1 when viewed in the radial direction of the firstclutch C1 (in the present example, in the same direction as the radialdirection R). In the present embodiment, the second hydraulic pressurecontrol device 82 is arranged in a position having a portionoverlapping, when viewed in the radial direction R, with all of theclutch hub 51, the piston 54, the friction members 53, the clutch drum(in the present example, the rotor holding portion 25), the operatingoil pressure chamber H1, and the circulating oil pressure chamber H2that constitute the first clutch C1. Note that the second hydraulicpressure control device 82 can also be structured to be arranged in aposition having a portion overlapping with only some of these members oroil pressure chambers when viewed in the radial direction R. In thiscase, the second hydraulic pressure control device 82 is preferablyarranged in a position having a portion overlapping, when viewed in theradial direction R, with at least the servo mechanism (in the presentexample, the piston 54, the urging member 55, and the operating oilpressure chamber H1).

The second hydraulic pressure control device 82 is provided with aplurality of hydraulic pressure control valves and a valve body 83provided with oil passages that communicates with the hydraulic pressurecontrol valves. In the present embodiment, as shown in FIG. 3, the oildischarged by the hydraulic pump 9 is supplied to the second hydraulicpressure control device 82 via the first hydraulic pressure controldevice 81 and the third oil passage A3. As described above, the thirdoil passage A3 is supplied with the line pressure controlled by thefirst hydraulic pressure control device 81, and the second hydraulicpressure control device 82 supplies the controlled hydraulic pressure tothe first clutch C1. Specifically, as shown in FIG. 6, the secondhydraulic pressure control device 82 is provided, as the hydraulicpressure control valves, with a first hydraulic pressure control valve41 and a second hydraulic pressure control valve 42. The first hydraulicpressure control valve 41 is a hydraulic pressure control valve thatcontrols the hydraulic pressure supplied to the operating oil pressurechamber H1 of the first clutch C1. The second hydraulic pressure controlvalve 42 is a hydraulic pressure control valve that controls (regulates)the hydraulic pressure supplied to the circulating oil pressure chamberH2 of the first clutch C1.

The first hydraulic pressure control valve 41 is, in the presentembodiment, a linear solenoid valve that has an electromagnetic portionand a pressure regulating portion. Here, the electromagnetic portion isa portion serving as an actuator that controls the position of a valveelement (spool). The pressure regulating portion is a portion serving asa valve. The pressure regulating portion is inserted in a valve inserthole formed in the valve body 83. The first hydraulic pressure controlvalve 41 is provided with an input port 41 a from which the oil at theline pressure is supplied, an output port 41 b from which the oil isdischarged to the first oil passage A1, a feedback port 41 c forgenerating feedback pressure, and a first discharge port 41 d and asecond discharge port 41 e from which the oil is discharged (drained).The oil at a pressure depending on the energized state of theelectromagnetic portion is supplied to the operating oil pressurechamber H1 of the first clutch C1 via the first oil passage A1. Thus,the first hydraulic pressure control valve 41 is structured so as tocommunicate with both of the first oil passage A1 and the third oilpassage A3, and the valve body 83 is formed with a part of the first oilpassage A1 and a part of the third oil passage A3.

The first discharge port 41 d of the first hydraulic pressure controlvalve 41 has a function to appropriately discharge oil toward a thirdhydraulic pressure control valve 43 for adjusting the amount of oilsupplied from the output port 41 b to the first oil passage A1 dependingon the feedback pressure. The first discharge port 41 d has also afunction to discharge a part of oil from the first oil passage A1 towardthe third hydraulic pressure control valve 43 for causing the hydraulicpressure supplied to the operating oil pressure chamber H1 to reduce.Here, the third hydraulic pressure control valve 43 is a valve thatcommunicates an input port with an output port of the third hydraulicpressure control valve 43 when the hydraulic pressure supplied to theinput port of the third hydraulic pressure control valve 43 is apredetermined pressure or higher. That is, the third hydraulic pressurecontrol valve 43 serves as a drain stopper of the oil in the first oilpassage A1, and also serves as a check valve that restricts the oil fromflowing backward from the third hydraulic pressure control valve 43toward the first hydraulic pressure control valve 41. The oil outputfrom the output port of the third hydraulic pressure control valve 43 isdischarged into the second housing space S2. The second discharge port41 e of the first hydraulic pressure control valve 41 has a function todischarge oil in a spring chamber to the second housing space S2 whenthe oil in the spring chamber is at a high pressure.

The second hydraulic pressure control valve 42 is, in the presentembodiment, is a type of pressure regulating valve which opens andcloses both an input port 42 a and a first discharge port 42 d. Thesecond hydraulic pressure control valve 42 is provided with the inputport 42 a from which the oil at the line pressure is supplied, an outputport 42 b from which the oil is discharged (drained) to the second oilpassage A2, a feedback port 42 c for generating feedback pressure, andthe first discharge port 42 d and a second discharge port 42 e fromwhich the oil is discharged (drained). After being controlled by thesecond hydraulic pressure control valve 42, the hydraulic pressure issupplied to the circulating oil pressure chamber H2 of the first clutchC1 via the second oil passage A2. The first discharge port 42 d of thesecond hydraulic pressure control valve 42 has a function toappropriately discharge oil to the second housing space S2 for adjustingthe amount of oil supplied from the output port 42 b to the second oilpassage A2 depending on the feedback pressure. The second discharge port42 e of the second hydraulic pressure control valve 42 has a function todischarge oil in a spring chamber to the second housing space S2 whenthe oil in the spring chamber is at a high pressure. Thus, the secondhydraulic pressure control valve 42 is structured so as to communicatewith the second oil passage A2, and the valve body 83 is formed with apart of the second oil passage A2.

As shown in FIG. 3, the second housing space S2 communicates with alower portion of the first housing space S1 (rotary electric machinehousing space SG) via the first communicating oil passage AC. As shownin FIG. 3, in the present embodiment, the first communicating oilpassage AC is constituted by a first hole portion P1 that is formed inthe first peripheral wall 34 a of the first case portion 3 a and thatcommunicates an outer circumferential surface of the first peripheralwall 34 a with an inner circumferential surface thereof. It should benoted that the first communicating oil passage AC (first hole portionP1) is formed at a portion having a small thickness in the radialdirection R of the first peripheral wall 34 a. Thereby, the length ofthe first communicating oil passage AC can be suppressed to be small soas to suppress the flow resistance of oil in the first communicating oilpassage AC to be small. In the present example, the first communicatingoil passage AC is an oil passage having almost the same size in flowpassage width and flow passage length. In the present embodiment, thefirst communicating oil passage AC corresponds to a “communicating oilpassage” in the present invention.

The second housing space S2 is formed as a space partitioned off so asto be oil-tight at portions other than the first communicating oilpassage AC so that the oil can be discharged from the second housingspace S2 only through the first communicating oil passage AC. The secondhousing space S2 is located below the first housing space S1 (rotaryelectric machine housing space SG), and thus, the first communicatingoil passage AC is formed in an upper portion (ceiling portion) of thesecond housing space S2. Consequently, the second housing space S2 isbasically in a state of being filled with oil, and thus, the oildischarged from an oil discharge port of the second hydraulic pressurecontrol device 82 is discharged to the first housing space S1 locatedthereabove via the first communicating oil passage AC. Here, in thepresent embodiment, the “oil discharge port” of the second hydraulicpressure control device 82 is constituted by the first discharge port 41d and the second discharge port 41 e of the first hydraulic pressurecontrol valve 41, and by the first discharge port 42 d and the seconddischarge port 42 e of the second hydraulic pressure control valve 42.

Thereby, while the hydraulic pump 9 is rotating, the second housingspace S2 is filled with oil, and the first housing space S1 (rotaryelectric machine housing space SG) is placed in a state in which oil isaccumulated up to a lower portion thereof, as shown by an example inFIG. 3. The first housing space S1 which communicates with the secondhousing space S2 via the first communicating oil passage AC is placed inthe state in which oil is accumulated basically only in the lowerportion thereof. Therefore, even when oil at a high pressure isdischarged from the oil discharge port of the second hydraulic pressurecontrol device 82 to the second housing space S2, a change in hydraulicpressure can be absorbed by a change in oil surface level in the firsthousing space S1 so as to suppress the hydraulic pressure in the secondhousing space S2 from rising rapidly.

In the present embodiment, as shown in FIG. 4, a flow path of oil isformed such that after oil is supplied to the circulating oil pressurechamber H2 of the first clutch C1 via the second oil passage A2, the oilis supplied to the coil end portions Ce of the rotary electric machineMG via the bearing 96. Thereby, it is possible to cool the bearing 96supporting the rotor Ro and to cool the rotary electric machine MGincluding the coil end portions Ce with the oil supplied to thecirculating oil pressure chamber H2. Thus, the present embodiment isstructured such that the oil discharged by the hydraulic pump 9 issupplied to the rotary electric machine MG.

As shown in FIG. 3, the oil supplied to the rotary electric machine MGis retained in the lower portion of the first housing space S1 (rotaryelectric machine housing space SG). The lower portion of the firsthousing space S1 communicates, via the first communicating oil passageAC, with the oil discharge port of the second hydraulic pressure controldevice 82 arranged in the second housing space S2. That is, in thepresent embodiment, a part (specifically, a part of the lower side) ofthe first housing space S1 (rotary electric machine housing space SG)constitutes a second oil retaining portion U2 that is provided so as tocommunicate with both of the oil discharge port of the second hydraulicpressure control device 82 and the first housing space S1.

As shown in FIG. 5, the oil retained in the second oil retaining portionU2 is discharged to the first oil retaining portion U1 via a dischargeoil passage AD. The discharge oil passage AD is formed, in the presentembodiment, so as to penetrate the joint portion 5 of the first caseportion 3 a and the second case portion 3 b and so as to extend towardboth sides in the axial direction L. The discharge oil passage AD isalso formed, in the present embodiment, so as to overlap with the thirdoil passage A3 in a position in the up-down direction at a differenthorizontal location from that of the third oil passage A3. Therefore,the discharge oil passage AD is shown by dashed lines in FIGS. 2 and 3.

The discharge oil passage AD has, as shown in FIG. 5, a second openingAEo that opens to the first housing space S1 having the second oilretaining portion U2 and a first opening ADo that opens to the firsthydraulic pressure control device housing space having the first oilretaining portion U1. Specifically, the discharge oil passage AD isprovided with a main body oil passage that extends in the horizontaldirection (specifically, in the axial direction L) and a secondcommunicating oil passage AE that extends in a direction inclined (inthe present example, inclined by approximately 45 degrees) relative tothe horizontal direction. The main body oil passage is formed so as tobe provided with the first opening ADo at an end on the second axialdirection L2 side, and so as to communicate with the secondcommunicating oil passage AE at a portion on the first axial directionL1 side relative to the joint portion 5. Specifically, the main body oilpassage is structured by connecting, in the axial direction L, a thirdhole portion P3 that is formed in the first peripheral wall 34 a andextends in the axial direction L with a fourth hole portion P4 that isformed in the second peripheral wall 34 b and extends in the axialdirection L.

The second communicating oil passage AE is formed so as to be provided,at an upper end thereof, with the second opening AEo, and so as to beopened, at a lower end thereof, to an upper surface portion (ceilingportion) of the main body oil passage. Specifically, the secondcommunicating oil passage AE is formed by a second hole portion P2through which the inner circumferential surface of the first peripheralwall 34 a communicates with the upper surface portion of the third holeportion P3 constituting the main body oil passage. A seal member isprovided around the penetrating portion (connecting portion of the thirdhole portion P3 and the fourth hole portion P4 in the joint portion 5)of the joint portion 5 in the discharge oil passage AD, and thus, theoil in the discharge oil passage AD is suppressed from leaking out ofthe case 3 via the joint portion 5. As shown in FIG. 3, a seal member isalso provided around a penetrating portion of the joint portion 5 in thethird oil passage A3, and thus, the oil in the third oil passage A3 issuppressed from leaking out of the case 3 via the joint portion 5.

As shown in FIG. 5, the second opening AEo is located above the firstopening ADo. In other words, an upper end portion of the secondcommunicating oil passage AE is located above a lower end portion B ofthe first opening ADo. In addition, while the hydraulic pump 9 isrotating, the oil level in the first oil retaining portion U1 isbasically located below the lower end portion B of the first openingADo. Thereby, the simple structure using gravity can efficiently returnthe oil in the second oil retaining portion U2 to the first oilretaining portion U1 connected to a suction oil passage (not shown) ofthe hydraulic pump 9, without providing a dedicated pump or the like inthe discharge oil passage AD. Although the oil level in the first oilretaining portion U1 depends on, for example, the amount andcharacteristics (such as viscosity) of oil circulated in the case 3 andthe rotational speed of the pump drive shaft 67, the lower end portion Bof the first opening ADo is preferably structured to be located abovethe highest oil level in the first oil retaining portion U1 while thehydraulic pump 9 is rotating.

As described above, the second opening AEo is located above the firstopening ADo. Moreover, in the present embodiment, the cross-sectionalarea of the second communicating oil passage AE is set so that theallowable flow rate of oil in the second communicating oil passage AE isgreater than the supply rate of oil to the second oil retaining portionU2. In addition, as described above, the oil supplied to the rotaryelectric machine MG and the oil discharged from the oil discharge portof the second hydraulic pressure control device 82 are supplied to thesecond oil retaining portion U2. Thereby, the oil level in the secondoil retaining portion U2 is basically determined by the height (positionin the up-down direction) of the upper end portion of the secondcommunicating oil passage AE (that is, the second opening AEo), andspecifically, determined to be at almost the same height as that of theupper end portion of the second communicating oil passage AE.Furthermore, in the present embodiment, as shown in FIG. 5, the secondcommunicating oil passage AE is formed so that the second opening AEo islocated below the lowermost portion of the inner circumferential surfaceof the stator St (specifically, a stator core). Thereby, even while thehydraulic pump 9 is rotating, the oil level in the second oil retainingportion U2 can be suppressed from being located higher than thelowermost portion of the inner circumferential surface of the stator St,thus making it possible to reduce a rotational resistance of the rotorRo.

In the present embodiment, the oil suctioned from the first oilretaining portion U1 and discharged by the hydraulic pump 9 is suppliedto both of the first hydraulic pressure control device 81 and the secondhydraulic pressure control device 82. In addition, as described above,the oil cooler is provided in the circulation path of the oil flowingthrough the hydraulic pump 9, the first hydraulic pressure controldevice 81, the torque converter TC, and the speed change mechanism TM.Therefore, the temperature of the oil retained in the first oilretaining portion U1 is maintained at a predetermined temperature orlower. This makes it easy to supply the oil to the rotary electricmachine MG at an oil temperature capable of cooling the rotary electricmachine MG without providing an oil cooler in the flow path of oilbetween the second hydraulic pressure control device 82 and the rotaryelectric machine MG.

4. Other Embodiments

Finally, other embodiments of the vehicle drive device according to thepresent invention will be described. Note that each structure to bedisclosed in each embodiment below can be applied in combination withany structure disclosed in another embodiment, unless any contradictionoccurs.

(1) In the above embodiment, the description has been made by taking anexample of the structure in which the oil discharged by the hydraulicpump 9 is supplied to the second hydraulic pressure control device 82via the first hydraulic pressure control device 81 the third oil passageA3. However, embodiments of the present invention are not limited tothis example, but the vehicle drive device can also be structured suchthat the second hydraulic pressure control device 82 is provided withthe line pressure control valve, and the oil discharged by the hydraulicpump 9 is directly supplied to the second hydraulic pressure controldevice 82, not passing through the first hydraulic pressure controldevice 81.

(2) In the above embodiment, the description has been made by taking anexample of the structure in which the oil discharged from the oildischarge port of the second hydraulic pressure control device 82 isdischarged to the second oil retaining portion U2, and then dischargedto the first oil retaining portion U1 via the discharge oil passage ADthrough which the first housing space S1 communicates with the first oilretaining portion U1. However, embodiments of the present invention arenot limited to this example, but the vehicle drive device can also bestructured such that the oil discharged from the oil discharge port ofthe second hydraulic pressure control device 82 is discharged to thefirst oil retaining portion U1 via a separate oil passage other than thedischarge oil passage AD. For example, such a structure may be employedif the second hydraulic pressure control device 82 is arranged above thelower end portion of the first hydraulic pressure control device 81. Inthis case, the structure can be made such that the oil is passed throughthe separate oil passage by using, for example, the discharge pressureof the second hydraulic pressure control device 82 in addition to thegravity acting on the oil.

(3) In the above embodiment, the description has been made by taking anexample of the structure in which the second hydraulic pressure controldevice 82 is fixed to the lower portion of the case 3 (in the presentexample, the first case portion 3 a). However, embodiments of thepresent invention are not limited to this example, but the vehicle drivedevice can also be structured such that the second hydraulic pressurecontrol device 82 is fixed to, for example, a side face portion of theperipheral wall 34 (a portion having a surface facing a horizontaldirection on the outer circumferential portion of the peripheral wall34) of the case 3. In this case, the structure can be made such that thesecond housing space S2 is formed by the first case portion 3 a and aside cover covering the side face portion of the case 3 to which thesecond hydraulic pressure control device 82 is fixed, instead of beingformed by the first case portion 3 a and the second oil pan 12. In sucha case, the structure is preferably such that at least a part of theelectromagnetic portion of the first hydraulic pressure control valve 41is located below the oil level, and that the oil discharge port of thesecond hydraulic pressure control device 82 (specifically, a portionwhere the oil discharge port opens to the outside of the secondhydraulic pressure control device 82) is located above the oil level.With such a structure, the electromagnetic portion can be cooled, andthe discharge resistance of oil at the oil discharge port can besuppressed to be small. The structure can also be made such that thesecond hydraulic pressure control device 82 is fixed to an upper portionof the peripheral wall 34 (a portion having an upward facing surface onthe outer circumferential portion of the peripheral wall 34) of the case3.

(4) In the above embodiment, the description has been made by taking anexample of the structure in which the second hydraulic pressure controldevice 82 is arranged in a position having a portion overlapping withthe rotary electric machine MG when viewed in the radial direction ofthe rotary electric machine MG. However, embodiments of the presentinvention are not limited to this example, but the vehicle drive devicecan also be structured such that the second hydraulic pressure controldevice 82 is arranged in a position different from that of the rotaryelectric machine MG in the axial direction of the rotary electricmachine MG, so as not to have a portion overlapping with the rotaryelectric machine MG when viewed in the radial direction of the rotaryelectric machine MG.

(5) In the above embodiment, the description has been made by taking anexample of the structure in which the second hydraulic pressure controldevice 82 is arranged in a position having a portion overlapping withthe first clutch C1 when viewed in the radial direction of the firstclutch C1. However, embodiments of the present invention are not limitedto this example, but the vehicle drive device can also be structuredsuch that the second hydraulic pressure control device 82 is arranged ina position different from that of the first clutch C1 in the axialdirection of the first clutch C1, so as not to have a portionoverlapping with the first clutch C1 when viewed in the radial directionof the first clutch C1.

(6) In the above embodiment, the description has been made by taking anexample of the case in which a part (specifically, a part of the lowerside) of the first housing space S1 constitutes the second oil retainingportion U2 that is provided so as to communicate with both of the oildischarge port of the second hydraulic pressure control device 82 andthe first housing space S1 (rotary electric machine housing space SG).However, embodiments of the present invention are not limited to thisexample, but the vehicle drive device can also be structured such thatthe second oil retaining portion U2 is formed in a space formed belowthe first housing space S1 and on the radially outward direction R2 siderelative to the first peripheral wall 34 a.

(7) In the above embodiment, the description has been made by taking anexample of the structure in which the case 3 is formed such that thecase 3 is separable into the first case portion 3 a forming the firsthousing space S1 (rotary electric machine housing space SG) and thesecond case portion 3 b forming the speed change mechanism housing spaceSM. However, embodiments of the present invention are not limited tothis example, but it is possible to appropriately change a part at whichthe case 3 is separable.

(8) In the above embodiment, the description has been made by taking anexample of the structure in which the rotary electric machine MG thetorque converter TC, and the speed change mechanism TM are arranged inthis order in the second axial direction L2 from the first axialdirection L1 side. However, embodiments of the present invention are notlimited to this example, but the vehicle drive device can also bestructured such that the torque converter TC, the rotary electricmachine MG and the speed change mechanism TM are arranged in this orderin the second axial direction L2 from the first axial direction L1 side.In the above embodiment, the description has been made by taking anexample of the structure in which all of the rotary electric machine MGthe torque converter TC, and the first clutch C1 are arranged on thefirst axial direction L1 side relative to the speed change mechanism TM.However, the structure can also be made such that at least any one ofthe rotary electric machine MG, the torque converter TC, and the firstclutch C1 is arranged on the second axial direction L2 side relative tothe speed change mechanism TM.

(9) In the above embodiment, the description has been made by taking anexample of the structure in which the oil supplied from the secondhydraulic pressure control device 82 to the circulating oil pressurechamber H2 of the first clutch C1 is discharged from the circulating oilpressure chamber H2, and then, supplied to rotary electric machine MG.However, embodiments of the present invention are not limited to thisexample, but the vehicle drive device can also be structured such thatthe oil discharged from the circulating oil pressure chamber H2 is notsupplied to the rotary electric machine MG, but directly returned to thefirst oil retaining portion U1 via an oil passage.

(10) In the above embodiment, the description has been made by taking asan example the structure in which the second hydraulic pressure controldevice 82 is provided with the second hydraulic pressure control valve42, and the hydraulic pressure controlled by the second hydraulicpressure control valve 42 is supplied to the circulating oil pressurechamber H2 of the first clutch C1. However, embodiments of the presentinvention are not limited to this example, but the vehicle drive devicecan also be structured such that the hydraulic pressure controlled bythe second hydraulic pressure control device 82 is supplied only to theoperating oil pressure chamber H1 of the first clutch C1.

(11) In the above embodiment, the description has been made by taking anexample of the structure in which the rotary electric machine housingspace SG, the fluid coupling housing space SC, and the speed changemechanism housing space SM are formed as spaces independent from oneanother. However, embodiments of the present invention are not limitedto this example, but the vehicle drive device can also be structuredsuch that the rotary electric machine housing space SG and the fluidcoupling housing space SC are formed in an integrated manner if oilflows in a limited flow path in the rotary electric machine housingspace SG. In the above embodiment, the description has been made bytaking an example of the structure in which the rotary electric machineMG is housed in the first housing space S1. However, the structure canalso be made such that the rotary electric machine MG is housed in aspace formed in a position different from that of the first housingspace S1 in the axial direction L, that is, such that the rotaryelectric machine housing space SG is formed as a space independent fromthe first housing space S1 in a position different from that of thefirst housing space S1 in the axial direction L.

(12) In the above embodiment, the description has been made by taking anexample of the structure in which the vehicle drive device 1 has asingle-axis structure, and all of the input shaft I, the first clutchC1, the rotary electric machine MG the torque converter TC, theintermediate shaft M, the speed change mechanism TM, and the outputshaft O are arranged on the same axis. However, embodiments of thepresent invention are not limited to this example, but the vehicle drivedevice 1 can also be structured as a drive device having a multi-axisstructure by arranging at least any one of the input shaft I, the firstclutch C1, the rotary electric machine MG the torque converter TC, theintermediate shaft M, and the output shaft O on an axis different fromthat of the speed change mechanism TM. Such a drive device having amulti-axis structure is preferable if the vehicle drive device 1 isfurther provided with a counter gear mechanism. Such a structureprovided with a counter gear mechanism is suitable when mounted on avehicle of an FF (front engine, front drive) type.

(13) In the above embodiment, the description has been made by taking anexample of the structure in which the hydraulic pressure controlled bythe first hydraulic pressure control valve 41 of the second hydraulicpressure control device 82 is directly supplied to the operating oilpressure chamber H1 of the first clutch C1. However, embodiments of thepresent invention are not limited to this example, but the vehicle drivedevice can also be structured such that a separate hydraulic pressurecontrol valve (not shown) other than the first hydraulic pressurecontrol valve 41 is provided, and the hydraulic pressure controlled(regulated) by the separate hydraulic pressure control valve is suppliedto the operating oil pressure chamber H1 of the first clutch C1. In thiscase, the structure is preferably such that the separate hydraulicpressure control valve operates using as signal pressure the hydraulicpressure controlled by the first hydraulic pressure control valve 41 soas to serve as a pressure regulating valve that regulates the linepressure, and the separate hydraulic pressure control valve is providedin the second hydraulic pressure control device 82.

(14) In the above embodiment, the description has been made by taking anexample of the structure in which the first hydraulic pressure controldevice housing space that houses the first hydraulic pressure controldevice 81 is formed as a space surrounded by the second case portion 3 band the first oil pan 11 mounted to the lower portion of the second caseportion 3 b. However, embodiments of the present invention are notlimited to this example, but the first hydraulic pressure control devicehousing space can also be structured to be formed by only a portion ofthe case 3 formed integrally with the second case portion 3 b (forexample, structured to be formed inside the peripheral wall of thesecond case portion 3 b).

(15) In the above embodiment, the description has been made by taking anexample of the structure in which the second housing space S2 thathouses the second hydraulic pressure control device 82 is formed as aspace surrounded by the first case portion 3 a and the second oil pan 12mounted to the lower portion of the first case portion 3 a. However,embodiments of the present invention are not limited to this example,but the second housing space S2 can also be structured to be formed byonly a portion of the case 3 formed integrally with the first caseportion 3 a (for example, structured to be formed inside the peripheralwall of the first case portion 3 a).

(16) In the above embodiment, the description has been made by taking anexample of the structure in which the vehicle drive device 1 isprovided, as a fluid coupling, with the torque converter TC having atorque amplifying function. However, embodiments of the presentinvention are not limited to this example, but the vehicle drive device1 can also be structured to be provided with a fluid coupling having notorque amplifying function instead of the torque converter TC, or thevehicle drive device 1 can be structured to be provided with no fluidcoupling.

(17) Regarding also other structures, the embodiments disclosed in thepresent specification are examples in all respects, and embodiments ofthe present invention are not limited to these examples. That is, anystructure not described in the claims of the present application can bechanged as appropriate within the scope not departing from the purposeof the present invention.

The present invention can preferably be used for a vehicle drive deviceprovided with an input member drivingly connected to an internalcombustion engine, a rotary electric machine, a speed change mechanismdrivingly connected to the rotary electric machine, an output memberdrivingly connected to the speed change mechanism and wheels, and anengagement device that is capable of changing the state of engagementbetween the input member and the speed change mechanism.

What is claimed is:
 1. A vehicle drive device comprising: an input shaftdrivingly connected to an internal combustion engine; a rotary electricmachine; a transmission drivingly connected to the rotary electricmachine and configured to change a speed ratio between the rotaryelectric machine and an output shaft; the output shaft being drivinglyconnected between the transmission and wheels; an engagement couplingconfigured to change a state of engagement between the input shaft andthe transmission; a first hydraulic pressure control valve that supplieshydraulic pressure to the transmission; a second hydraulic pressurecontrol valve that is provided separately from the first hydraulicpressure control valve, and that supplies hydraulic pressure to theengagement coupling; a first case portion that houses the rotaryelectric machine and the engagement coupling; a second case portion thathouses the transmission; wherein the first hydraulic pressure controlvalve is provided at a lower portion of the second case portion, and thesecond hydraulic pressure control valve is provided at a lower portionof the first case portion.